Single tube binary counter



Dec. 15, 1953 B. M. GORDON 2,662,983

SINGLE TUBE BINARY COUNTER Filed June 9, 1951 INVENTOR. BERNARD M. GORDON Asymmetrical Conducting Element (e.g. Thermionig or Crystal Diode) 4 k ATTORNEY Patented Dec. 15, 1953 ITED STATE grist FFICE SINGLE TUBE BINARY COUNTER Bernard M. Gordon, Philadelphia, Pa., assignor to Eckert-Mauchly Computer Corporation,

Philadelphia, Pa., a corporation of Pennsyl- Vania Application J ans 9, 1951, Serial No. 230,790

8 Claims.

. This invention relates in general to electronic computing apparatus, and is directed in general to the provision of an improved binary counting circuit which will effect a substantial simplification and elimination of circuit components hitherto deemed essential.

Before describing the functions and objectives attained in accordance with the precepts of the invention, it may be pointed out that in modern electronic computing apparatus, an enormous number of vacuum tubes are customarily employed with a corresponding complexity of circuity, increased liability of component failure and heavy current consumption. As is wellv known, the average vacuum tube has a comparatively limited life, in view of the deterioration and/or failure of the filament and cathode elements. Replacements of the tubes on an extensive scale, therefore, it will be understood, are frequently required.

Recently, a reduction in the number of vacuum tubes used in electronic computing apparatus has been made possible, by substituting crystal diode rectifiers wherever feasible. Nevertheless, the associated circuits of the electronic computing apparatusstill require many thousands of these tubes and the saving, therefore, made possible by the teachings of the present invention, will be appreciated in view of the many parallelisms of circuity throughout the computing apparatus.

A salient object of the invention is to provide a single tube binary counter which will perform the functions of the customary two-tube binary counter.

Another object is the provision of a single tube binary counter having a single rectifier gate.

Another object is the simplification of the circuity in electronic computing apparatus.

A further object is to effect a substantial saving in cost and material in electronic computing apparatus, whereby a single electron tube, optionally employing one or two rectifier gates in accordance with this invention, may perform all the functions of a conventional two-tube binary counter with its several rectifier gates. Other objects and advantages residing in the novel circuity and in the arrangement and disposition of parts will appear as the description proceeds and will be best understood when taken in connection with the accompanying drawings wherein:

Figure 1 is a diagrammatic representation of a single tube binary counter embodying one form of the invention; and

Figure 2 is a modified form of the circuit illus- 2 trated in Figure 1 and showing a further simplification and the elimination of additional components while achieving an efficient operative assembly.

Approximate values of potentials, resistances and capacities employed are designated in the drawing for convenience of understanding of the circuity.

Referring now to the drawings wherein similar reference characters indicate corresponding parts, the numeral H designates an electron tube, such as a thyratron, having operatively coupled thereto a pair of crystal diode gates, designated generally at I 2 and it, respectively. 7. The gate l2 includes a pair of conductively coupled crystal diodes l4, i5, and the resistor 46. One terminal'of the resistor it is connected to ground I7, and the other terminal to a point it common tothe cathode terminals of the two diodes.

The diode M has an anode terminal connected to a lead from an input conducting line 29 which is connected in turn through a resistor 2! to a source of high potential, as at 2.2. The input line includes a coupling capacitor 23 in series therewith. The anode terminal of diode I5 is connected to a conductor 24 associated with the anode Ila of the thyratron i l, as hereinafter described.

The gate l3 also has a pair of conductively coupled crystal diodes 25, 25 and includes the resistor 21; The common junction point 28 of the cathodes of the diodes 25, 26 is biased from a source of negative polarity 29 through lead 353 and resistor 21. The anode terminal of the diode 25 is connected to the input conducting line 2%.

The anode of crystal diode 25 is connected to a lead 32 associated with the cathode Nb of the thyratron at a junction point 33 located between two serially connected resistors 35, 35 on the same lead. The upper terminal of resistor 34 is directly connected to the cathode i ii) of the thyratron, while the lower terminal of resistor 35 is connected to ground 36. V The anode Ha of the thyratron, whose control grid He is negatively biased from a suitable source 37, is connected to an adjacent terminal of a resistor 38 whose other terminal is connectedto the serially associated resistors 39, 5.9, respectively on the conductor 2%. The outer terminal of the resistor til connects to a positive source of high potential l which may be, for example, 300 volts.

Capacitive coupling, between gate l 2 and anode Ila of the thyratron I! and between gate [3 and the cathode llb of the thyratron, is provided in th following manner:

In the case of gate [2, a coupling capacitor 42 is connected from junction point I8 between the cathodes of diodes I4, I across to the upper terminal of the resistance 38 connected to the anode lid of the thyratron.

In the case of gate l3, a coupling capacitor 43 is connected from point 28 common to the cathodes of the two diodes 25, 26, to the cathode HZ; of the thyratron.

The function and operation of the single tube binary counter has been in large measure indicated above, but may be summarized as follows:

Before energization, the thyratron H is in an initial nonconducting or zero state, the control oii bias. The power may now be assumed to be switched on. Prior to a pulse, the point 33 will be slightly negative, the control grid llc, as noted, being at cut-off bias and no current flowing from the anode of the thyratron. Point 33, therefore, will be :at a potential ineffective to inhibit the negative gate 13 formed by the crystal diodes 25, 2e and resistor 21.

Upon the occurrence of a negative pulse, indicated schematically at M, via the input post it and conducting line 20, the tendency to lower the potential at point i 8 and pass current through resistor It of the gate 12 will be checked at resistor it because of the latters comparatively high positive potential connection, and no pulse, accordingly, will be coupled through capacitor 42 to the anode of the thyratron.

However, the negative pulse will pass through gate is at the cathode of the thyratron and be coupled through capacitor 43 to the said cathode. When the potential of the cathode is thus lowered, the thyratron will fire and its grid ll c will lose control. tained its second stable state.

Inspection and consideration of the two gates; viz., I2 and It described above will now make clear that, since at the second stable state the cathode i lb is at high potential and hence point i 33 at high potential also, the cathode gate I3 is inhibited to negative pulses. At the same time, the anode gate 12 is no longer capable of inhibiting the input pulse because the gat input (diode id) is at a lowered potential. next negative pulse will be coupled to the anode, but not to the cathode, and will lower the said anode below conduction level of the thyratron. The general circuit will now return to its original condition. Further pulses will merely continue the cyclic permutation indicated. It will be understood that it is only necessary that the pulse applied continue long enough for recovery time (not deionization time) in order that the grid may regain control and the tube return to its original condition.

The form of the invention shown in Figure .2

The modified form of the invention not only achieves the saving of component parts eiiected by the first form of the invention described above, but in addition, by its novel functioning and Circuity further permits the elimination of one of the two rectifier gates and of the components normally associated with the eliminated gate. The simplification of circuity and the actual elimination of parts will be observed at first glance by comparison of the first form of the invention shown in Figure l with the simplified form of Figure 2.

The circuit will thus have 'at- Thus the Referring to the modified form of the inven-- tion, the numeral 59 designates the electron tube, which may be, as in the first form, a thyratron. The thyratron has coupled thereto a rectifier gate designated generally at 5i and including the serially connected crystal diodes 52, 53 and the resistor 54.

The resistor it is negatively biased from a source of potential 55 and is connected to the said diodes at a point 56 common to the cathodes of both. Th anode terminal of diode 52 is on the input conducting line 5? While the anode terminal of diode 53 is connected at point 58 between the two resistors 59, 68, joined in series, the last-named resistor so being grounded at iii.

The upper terminal of resistor 59 connects with the cathode eta of the thyratron whose grid 5th is normally biased from a source of negative polarity at 62 and through the resistor 63.

The inpin conducting line it, which may have a positive potential of, for example, 10 volts, is connected through diode junction point 56 and coupling capacitor it to anode 59a; and is also connected, via conductor 65 and coupling capacitor 55 and lead 6? to a junction point 68 on a lead 63 joining two serially connected resistors it, 12.

The outer or lower terminal of resistor H is joined to the anode etc of the thyratron., while the outer terminal of the resistor 12 is associated with the source of high potential 13.

The operation of the circuit embodying the modified form of the invention depicted in Figure 2 may be briefly explained as follows:

Assuming the electronic valve to be in a nonconducting state with at cut-off bias and point at ground potential and further assuming the operating potentials indicated have been applied, a negative pulse, as indicated schematically at M, via coupling capacitor and resistor 52, arriving at the anode etc be inhibited by virtue the high potential of the latter. Consequently, the thyratron will remain nonconductive.

As in the case of the first form of the invention, however, a negative pulse of proper potential will pass through gate ti and coupling capacitor t t and be operatively appiied to the cathode 56a, thereby lowering the potential of the latter and consequently relatively raising the potential of grid 5%. The thyratron will now fire and the grid 5% will lose control. The circuit, in this manner, will attain its second stable state, with the cathode at comparatively high potential and inhibitive to negative pulses. At the same time, since the anode by reason of the potential drop across the resistor i2 is now at lowered potential and, therefore, now susceptible to reduction below conduction level of the thyratron, the next negative pulse will extinguish the thyratron and the circuit will return to its original condition.

While the invention been described with particular reference to an'ordinary type of thyratron, it will be understood that it is equally adaptable with other types of tubes such as socalled hard or highly evacuated electron tubes, with appropriate substitutions of conventional circuit components.

It will, of course, be understood that the description and drawings herein contained are illustrative merely, and that various modifications and changes may be made in the structure disclosed without departing from the spirit of the invention.

What is claimed is:

1. In signal responsive apparatus, in combination, an electric valve, said valve having anode, cathode and grid elements, a first gate connected to said anode, a second gate connected to said cathode, and circuit components associated with said gates and elements and eflective to apply a pulse alternately to said anode and said cathode.

2. In signal responsive apparatus, comprising an electric valve, said valve having anode, grid and cathode elements, a single gate electrically connected to the anode and to the cathode elements, and a circuit associated with said gate, cathode and anode elements and efiective to alternately energize and de-energize the said tube.

3. In signal responsive apparatus, an electric valve having a cathode, a control electrode and an anode, a control signal line, a first gate controlled by the potential of said anode governing the passage of signals from said signal line to said anode, and a second gate controlled by the potential of said cathode governing the passage of signals from said signal'line to said cathode.

4. In signal responsive apparatus, in combination, an electric valve, said valve having anode, grid and cathode elements, a circuit associated with said elements and having a single rectifier gate, a pair of diodes included in said gate, a plurality of sources of potential operatively applied to said elements, a capacitor member associated with said anode element, a second capacitor associated with said cathode element, and resistances associated with said capacitors; said circuit being effective to apply negative pulses to the anode and alternately to the cathode.

5. A single tube binary counter comprising, in combination, a thyratron, said thyratron having anode, grid and cathode elements, a first gate connected to the anode element, a second gate connected to the cathode element, an input conductor electrically connected to said cathode and anode elements and effective to apply a negative pulse to said last-mentioned elements in alternation, and a plurality of sources of potential connected to said anode, grid and cathode elements.

6. A single tube binary counter comprising, in combination, a thyratron, said thyratron having anode, grid and cathode elements, a circuit associated with said elements and including a pair of gates, and a plurality of sources of potential applied to and biasing the said elements to predetermined initial voltages, said circuit being responsive to input pulses and effective to alternately flip the thyratron from one stable state to another with each input pulse.

'7. In a signal responsive device, an electric valve having an anode, a control element and a cathode, a control signal line, a reactor connecting said control signal line with said anode, a cathode, potential controlled gate connecting said control signal line with said cathode, and circuit connections for applying an exciting potential between said cathode and anode.

8. In signal responsive apparatus, an electric valve havin an anode, control element and cathode, a control signal line, an anode potential controlled gate reactively coupling said control signal line with said anode, a cathode potential controlled gate reactively coupling said control signal line with said cathode, and circuit connections for applying an exciting potential between said cathode and anode.

BERNARD M. GORDON.

Name Date Hadfield May 15, 1951 Number 

